What are the guidelines for administering Tdap (Tetanus, diphtheria, and pertussis) vaccine in pregnancy?

Tdap Vaccination Guidelines During Pregnancy

All pregnant women should receive Tdap vaccination during each pregnancy between 27-36 weeks gestation, preferably during the earlier part of this window (27-30 weeks), regardless of prior vaccination history. 1, 2

Timing of Tdap Administration

• Optimal timing: 27-36 weeks gestation

  • Vaccination at 27-30 weeks produces the highest antibody concentrations in newborns 3
  • Early vaccination within this window maximizes maternal antibody transfer to the infant 2
  • A minimum of 2 weeks is required after vaccination to mount a maximal immune response 1

• Rationale for third trimester timing:

  • Active transport of maternal immunoglobulin G does not substantially occur before 30 weeks gestation 1
  • Maternal antibodies wane quickly; women immunized during first or second trimester have low antibody levels at term 1
  • Tdap vaccination at 27-36 weeks is 85% more effective than postpartum vaccination in preventing pertussis in infants <8 weeks of age 4

Special Situations

1. Women due for tetanus booster during pregnancy:

   • If >10 years since previous Td, administer Tdap instead 1
   • Optimal timing remains 27-36 weeks gestation 1

2. Wound management during pregnancy:

   • If tetanus prophylaxis is indicated (≥5 years since previous booster), administer Tdap 1
   • This applies regardless of gestational age if clinically indicated 2

3. Pregnant women with unknown/incomplete tetanus vaccination:

   • Initiate 3-dose series: 0,4 weeks, and 6-12 months 1
   • Tdap should replace one dose of Td in this series, preferably at 27-36 weeks 1
   • Remaining doses can be either Td or Tdap 1

4. If Tdap not administered during pregnancy:

   • Administer immediately postpartum if woman has never received Tdap 1
   • Not necessary if woman has previously received Tdap 1

Safety and Efficacy

• Tdap vaccination during pregnancy is safe and effective 2
• FDA has approved Tdap specifically for "immunization during the third trimester of pregnancy to prevent pertussis in infants younger than 2 months of age" 5
• Studies show 80-91% efficacy in preventing pertussis in newborns 2
• No evidence of adverse fetal effects from vaccinating pregnant women with inactivated vaccines 6

Implementation Strategies

• Prenatal care providers should implement a Tdap immunization program for all pregnant women 1
• Vaccination rates are significantly higher when healthcare providers make direct recommendations 2, 7
• Tdap can be administered simultaneously with inactivated influenza vaccine during pregnancy 2
• Despite recommendations, actual Tdap vaccination rates during pregnancy have varied from 16-61% 7, though rates have increased substantially in recent years (from <1% before 2009 to 54% by 2015) 8

Cocooning Strategy

In addition to maternal vaccination, ACIP recommends that all close contacts of infants <12 months (parents, siblings, grandparents, caregivers) receive Tdap if they haven't previously received it 1, 2

Common Pitfalls to Avoid

• Delaying vaccination: Don't wait until late in the third trimester; vaccinate at the beginning of the 27-36 week window for optimal antibody transfer 2, 3
• Skipping vaccination due to prior Tdap: Tdap should be given during EACH pregnancy regardless of prior vaccination history 1, 2
• Referring out for vaccination: Practices not stocking the vaccine leads to missed opportunities; on-site administration is associated with higher vaccination rates 7
• Inadequate insurance coverage: Insurance reimbursement challenges can be barriers to implementation; practices should develop coding strategies to ensure proper reimbursement 7